In the Holy Land, Edessa has fallen, giving rise to a strong desire among bishops in England to end the civil war and redirect fighting men towards another Crusade to keep Jerusalem safe.

In the late summer of 1145, the younger son of Robert of Gloucester, Philip FitzRobert, switches sides, yielding his castle at Cricklade to King Stephen.

Philip's castellan at Faringdon, Brien de Soulis, quickly follows his example, surrendering his castle to Stephen's besieging forces.

Robert, Earl of Leicester is given a list of the thirty men and their captors, but one man among Faringdon's garrison is unaccounted for: Olivier de Bretagne.

In November 1145, Robert sends a copy of the list to Hugh Beringar, Sheriff of Shrewsbury, along with news that the two factions will meet for a peace conference at Coventry.

Riding to Coventry, barely have they entered the town when Yves draws his sword and flies in rage at Brien de Soulis, the turncoat castellan of Faringdon.

Defying a promise of safe conduct to all who came with the Empress, twelve men seize Yves near Gloucester, which is duly reported to the Bishop.

Cadfael must decide whether to continue searching for Olivier and Yves and break his monastic vows, or return with Hugh to Shrewsbury.

At Deerhurst Abbey, Cadfael meets a mason's assistant who identifies the seal as belonging to a captain of the garrison, Geoffrey FitzClare, loyal to the Empress.

His deputy shall surrender the castle and trade Philip to the Empress for the best terms he can get; he gives Cadfael the keys to Olivier's cell.

Kirkus Reviews finds this book to be one of the most moving adventures in this series: The ruinous civil war between King Stephen and the Empress Maud for 12th-century England brings added heartache to Brother Cadfael (The Holy Thief, 1993, etc.)

Persevere past the drumbeat of canned history in the opening chapter and you'll find the pace quickening to unfold one of Cadfael's most moving adventures, one that touches his own generous heart most closely.

[1]Publishers Weekly has high praise for the plot and depiction of strong emotions between friends: In Brother Cadfael's 20th chronicle, Peters deftly binds the medieval monk's new adventure with family ties, moving from issues intensely public to problems determinedly private.

Olivier de Bretagne, who (unknown to himself) is Brother Cadfael's son, has been taken prisoner during England's dynastic war between two grandchildren of William the Conqueror.

In twelfth-century Britain, a rebellion has arisen, with factional fighting between the knights supporting Empress Maud and those swearing allegiance to her cousin Stephen.

Philip FitzRobert, a traitor to the empress, has taken 30 hostages, among them a young man named Olivier de Bretagne, who is Cadfael's son from a chance encounter years earlier.

The quest becomes fraught with peril when Yves, Olivier's brother-in-law, is falsely accused of murder, and only Brother Cadfael can save him.

Many of the brothers introduced throughout the series appear and react to Cadfael's trip out of their cloister, including Prior Robert, his shadow Jerome, the precentor Anselm, among others.

At their second meeting (The Pilgrim of Hate), Cadfael shares the knowledge with his friend Hugh, who has come to like this knight in service to the other side.

Cadfael risked his settled life as a cloistered monk to save his son, a freighted choice, because he was a father before he was a brother, though he did not know it when he committed to the monastery.

Abbot Radulfus, head of the Abbey since 1138 (the end of Monk's Hood), met Olivier in The Pilgrim of Hate, learning in this story that Cadfael is his father.

King Stephen and his cousin Empress Maud and their supporters meet under the auspices of three major bishops at Coventry (Roger de Clinton, character in The Heretic's Apprentice, Henry of Winchester brother to the King and character in The Pilgrim of Hate, and Nigel of Ely), in another unsuccessful effort to move toward resolution and acceptance that just one can hold the crown of England at a time.

Cadfael, as observer to this chaos among the aristocracy of his adopted home of England, thinks how differently sons are viewed in his birthplace in Wales.

In both places, there are children born outside marriage: in England, those sons in particular can be educated, supported, have lands and power, but not succeed as king; in Wales, if acknowledged by the father, they have full rights.

Cadfael speculates on the possibly different path for England if the first son of old King Henry, the illegitimate Robert of Gloucester, had been recognised and accepted.

[6] In the Thames Valley, two of the Empress's castellans have defected to Stephen, bringing their castles and garrisons in Faringdon and Cricklade with them, most notably the younger son of Robert of Gloucester, Philip FitzRobert.

[7] At the meeting called by Bishop Roger de Clinton, most of the people active on each side of this dispute have speaking lines at the table, or later when advising Empress Maud in Gloucester.

This story includes a medieval siege of a castle,[8] lasting over two days, with the largest military force Empress Maud could muster, initially gathered to discuss the implications of the failed peace talks.

The Fall of Edessa in the Holy Land the previous December in 1144,[16] an event which led to the declaration of the Second Crusade, is much in the air, as bishops across Europe fear for the safety of Jerusalem.

The war over the English crown comes to an effective close three years later, in 1148, when Maud retreats to Normandy after Robert of Gloucester's death.